Light sources of higher luminance are used in greatly varying fields, for example, in endoscopy and also in projection devices, wherein gas discharge lamps are presently most widely distributed. In lighting applications, for example, projection or endoscopy, based on the fundamentally known LARP (“laser activated remote phosphor”) technology, a phosphor is irradiated by a laser. The laser radiation incident on the phosphor is partially converted by the phosphor by means of wavelength conversion into a wavelength-converted useful light and is partially scattered without a wavelength conversion.
In particular for video projection, the phosphors for the projector color channels red, green, and blue are typically applied to a rotating wheel, to distribute the laser power over a larger surface in chronological average and therefore to reduce the phosphor degradation.
Laser radiation is currently typically used in LARP technology. However, in the scope of the present disclosure, the term LARP is to be generalized such that other pump radiation sources suitable for phosphor excitation having comparable radiation properties as a laser, in particular its lesser beam divergence, are also included, for example, superluminescent diodes, optionally with or without downstream optics.
Document US 2011/0249460 A1 discloses a headlight for automobiles, using which various light distributions may be generated on the road. Two lasers are provided for this purpose, which each emit on a rectangular phosphor tablet via an associated MEMS mirror (MEMS: micro-electromechanical system). Each MEMS mirror can oscillate in two axes, whereby the two laser beams can in principle excite any point on the phosphor panel to luminescence. Depending on the desired light distributions, for example, distance light, traveling light, or curve light, at least one of the two lasers scans the phosphor panel in a corresponding irradiation pattern. With the aid of a projection optical system, the illumination pattern resulting from the irradiation pattern is projected from the phosphor panel onto the road. For specific lighting scenarios, both lasers having their associated mirror can also be in operation simultaneously, for example, for driving light with simultaneous curve light. In the event of failure of a laser-mirror pair, the remaining laser-mirror pair can also execute at least the basic functions alone.